What if there was another planet like earth? Based on the theories of Stephen Hawking, J. Craig Ventor, Michio Kaku, David Moriarty, and other brilliant scientific minds, the Discovery Channel special "Alien Planet" (2007) sends a pair of robots to Darwin IV, a planet 6.5 lights years from earth with an ecosystem similar to our own. The robots find a planet teeming with life unlike anything we’ve ever seen before in this speculative documentary.